#include <iostream>

using namespace std;

class CBase {
    public:
        // CBase ();
        virtual ~CBase () = 0;
};

class CDerived {
    public:
        // CDerived ();
       ~CDerived ();
};

// CBase :: CBase () {
// }
CBase :: ~CBase () {
}

// CDerived :: CDerived () {
// }
CDerived :: ~CDerived () {
}

int main () {
    CBase *bp = new CDerived;
    delete bp;
    
    return 0;
}
